Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
xang xa » lang xa, mang xa, ang xa
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
ve cam » ve cham, ve cac, ve cai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (toc sach)) ty xang xa hoi. hieu ((ve cam) or (va cam)) tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ty xang xa hoi. hieu ((ve cam) OR (va cam)) tuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ty xang xa hoi. hieu ((ve cam) or (va cam)) tuc va hanh vi cua tre*.